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authorBjörn-Egil Dahlberg <[email protected]>2011-12-07 23:37:11 +0100
committerBjörn-Egil Dahlberg <[email protected]>2011-12-08 14:12:03 +0100
commit965db6494f80e4c784aa3bb1cd96dd925ce8b284 (patch)
tree3fe61d9c128b67479af5b8e4f5fa19fa28a56936
parent9dd83933601f3c933718874c13d83ca952febc3f (diff)
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Document file:*_file_info/2
* file:read_file_info/2 * file:write_file_info/3 Document options and time behavior.
-rw-r--r--lib/kernel/doc/src/file.xml52
-rw-r--r--lib/kernel/src/file.erl10
2 files changed, 47 insertions, 15 deletions
diff --git a/lib/kernel/doc/src/file.xml b/lib/kernel/doc/src/file.xml
index c6a1f25dd9..b2e6962be8 100644
--- a/lib/kernel/doc/src/file.xml
+++ b/lib/kernel/doc/src/file.xml
@@ -150,6 +150,9 @@
<name name="mode"/>
</datatype>
<datatype>
+ <name name="file_info_option"/>
+ </datatype>
+ <datatype>
<name name="sendfile_option"/>
</datatype>
</datatypes>
@@ -412,7 +415,7 @@
<name>file_info(Filename) -> {ok, FileInfo} | {error, Reason}</name>
<fsummary>Get information about a file (deprecated)</fsummary>
<desc>
- <p>This function is obsolete. Use <c>read_file_info/1</c>
+ <p>This function is obsolete. Use <c>read_file_info/1,2</c>
instead.</p>
</desc>
</func>
@@ -1188,6 +1191,7 @@
</func>
<func>
<name name="read_file_info" arity="1"/>
+ <name name="read_file_info" arity="2"/>
<fsummary>Get information about a file</fsummary>
<desc>
<p>Retrieves information about a file. Returns
@@ -1199,6 +1203,20 @@
from which the function is called:</p>
<code type="none">
-include_lib("kernel/include/file.hrl").</code>
+ <p>The time type returned in <c>atime</c>, <c>mtime</c> and <c>ctime</c>
+ is dependent on the time type set in <c>Opts :: {time, Type}</c>.
+ Type <c>local</c> will return local time, <c>universal</c> will
+ return universal time and <c>posix</c> will return seconds since
+ or before unix time epoch which is 1970-01-01 00:00 UTC.
+ Default is <c>{time, local}</c>.
+ </p>
+ <note>
+ <p>
+ Since file times is stored in posix time on most OS it is
+ faster to query file information with the <c>posix</c> option.
+ </p>
+ </note>
+
<p>The record <c>file_info</c> contains the following fields.</p>
<taglist>
<tag><c>size = integer()</c></tag>
@@ -1213,15 +1231,15 @@
<item>
<p>The current system access to the file.</p>
</item>
- <tag><c>atime = <seealso marker="#type-date_time">date_time()</seealso></c></tag>
+ <tag><c>atime = <seealso marker="#type-date_time">date_time()</seealso> | integer() </c></tag>
<item>
- <p>The last (local) time the file was read.</p>
+ <p>The last time the file was read.</p>
</item>
- <tag><c>mtime = <seealso marker="#type-date_time">date_time()</seealso></c></tag>
+ <tag><c>mtime = <seealso marker="#type-date_time">date_time()</seealso> | integer() </c></tag>
<item>
- <p>The last (local) time the file was written.</p>
+ <p>The last time the file was written.</p>
</item>
- <tag><c>ctime = <seealso marker="#type-date_time">date_time()</seealso></c></tag>
+ <tag><c>ctime = <seealso marker="#type-date_time">date_time()</seealso> | integer() </c></tag>
<item>
<p>The interpretation of this time field depends on
the operating system. On Unix, it is the last time
@@ -1377,9 +1395,11 @@
</func>
<func>
<name name="read_link_info" arity="1"/>
+ <name name="read_link_info" arity="2"/>
<fsummary>Get information about a link or file</fsummary>
<desc>
- <p>This function works like <c>read_file_info/1</c>, except that
+ <p>This function works like
+ <seealso marker="#read_file_info/2">read_file_info/1,2</seealso> except that
if <c><anno>Name</anno></c> is a symbolic link, information about
the link will be returned in the <c>file_info</c> record and
the <c>type</c> field of the record will be set to
@@ -1690,6 +1710,7 @@
</func>
<func>
<name name="write_file_info" arity="2"/>
+ <name name="write_file_info" arity="3"/>
<fsummary>Change information about a file</fsummary>
<desc>
<p>Change file information. Returns <c>ok</c> if successful,
@@ -1700,18 +1721,25 @@
from which the function is called:</p>
<code type="none">
-include_lib("kernel/include/file.hrl").</code>
+ <p>The time type set in <c>atime</c>, <c>mtime</c> and <c>ctime</c>
+ is dependent on the time type set in <c>Opts :: {time, Type}</c>.
+ Type <c>local</c> will interpret the time set as local, <c>universal</c> will
+ interpret it as universal time and <c>posix</c> must be seconds since
+ or before unix time epoch which is 1970-01-01 00:00 UTC.
+ Default is <c>{time, local}</c>.
+ </p>
<p>The following fields are used from the record, if they are
given.</p>
<taglist>
- <tag><c>atime = <seealso marker="#type-date_time">date_time()</seealso></c></tag>
+ <tag><c>atime = <seealso marker="#type-date_time">date_time()</seealso> | integer()</c></tag>
<item>
- <p>The last (local) time the file was read.</p>
+ <p>The last time the file was read.</p>
</item>
- <tag><c>mtime = <seealso marker="#type-date_time">date_time()</seealso></c></tag>
+ <tag><c>mtime = <seealso marker="#type-date_time">date_time()</seealso> | integer()</c></tag>
<item>
- <p>The last (local) time the file was written.</p>
+ <p>The last time the file was written.</p>
</item>
- <tag><c>ctime = <seealso marker="#type-date_time">date_time()</seealso></c></tag>
+ <tag><c>ctime = <seealso marker="#type-date_time">date_time()</seealso> | integer()</c></tag>
<item>
<p>On Unix, any value give for this field will be ignored
(the "ctime" for the file will be set to the current
diff --git a/lib/kernel/src/file.erl b/lib/kernel/src/file.erl
index 7a48d34a09..b253b3e901 100644
--- a/lib/kernel/src/file.erl
+++ b/lib/kernel/src/file.erl
@@ -109,6 +109,10 @@
-type posix_file_advise() :: 'normal' | 'sequential' | 'random'
| 'no_reuse' | 'will_need' | 'dont_need'.
-type sendfile_option() :: {chunk_size, non_neg_integer()}.
+-type file_info_option() :: {'time', 'local'} | {'time', 'universal'}
+ | {'time', 'posix'}.
+
+
%%%-----------------------------------------------------------------
%%% General functions
@@ -218,7 +222,7 @@ read_file_info(Name) ->
-spec read_file_info(Filename, Opts) -> {ok, FileInfo} | {error, Reason} when
Filename :: name(),
- Opts :: list(),
+ Opts :: [file_info_option()],
FileInfo :: file_info(),
Reason :: posix() | badarg.
@@ -240,7 +244,7 @@ read_link_info(Name) ->
-spec read_link_info(Name, Opts) -> {ok, FileInfo} | {error, Reason} when
Name :: name(),
- Opts :: list(),
+ Opts :: [file_info_option()],
FileInfo :: file_info(),
Reason :: posix() | badarg.
@@ -266,7 +270,7 @@ write_file_info(Name, Info = #file_info{}) ->
-spec write_file_info(Filename, FileInfo, Opts) -> ok | {error, Reason} when
Filename :: name(),
- Opts :: list(),
+ Opts :: [file_info_option()],
FileInfo :: file_info(),
Reason :: posix() | badarg.